Puddling intensity for late-season sawah systems based on soil hydrophysical conditions and rice performance

Lowland sawah farmers often puddle to improve soil hydrophysical conditions for rice, but the puddling intensity beyond which no extra yield increases occur is unknown. Agro- nomic effects of six mechanical puddling intensities were assessed in three Nigerian inland-valley bottoms. All puddled plots, irrespec- tive of intensity, produced similar effects at all three locations. At 10 days after transplanting, soil bulk density of all puddled plots re- presented mean decreases relative to control plots of about 22.4, 15.8, and 31.7% at Akaeze, Adani, and Ejeti, respectively. Soil bulk density and moisture content upon saturation were similar during 40-120 days after transplanting. All puddled plots consistently showed taller plants and greater tillering than control plots only at Ejeti. Grain yields were similar among treatments in Akaeze and Adani (mean, 3.71 and 6.42 Mg ha -1 , respectively), but one-pass puddling yielded numerically highest in both locations. At Ejeti, grain yields followed the trend for plant growth, with mean values of 4.36 and 1.81 Mg ha -1 for puddled and control plots, respecti- vely. One-pass puddling may be sufficient for sawah rice grown late particularly in less humid environments.